Source/charon/encoding/payloads/nonce_payload.c

   1 /**
   2  * @file nonce_payload.h
   3  *
   4  * @brief Implementation of nonce_payload_t.
   5  *
   6  */
   7
   8 /*
   9  * Copyright (C) 2005 Jan Hutter, Martin Willi
  10  * Hochschule fuer Technik Rapperswil
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License as published by the
  14  * Free Software Foundation; either version 2 of the License, or (at your
  15  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  * for more details.
  21  */
  22
  23 /* offsetof macro */
  24 #include <stddef.h>
  25
  26 #include "nonce_payload.h"
  27
  28 #include <encoding/payloads/encodings.h>
  29 #include <utils/allocator.h>
  30
  31
  32 typedef struct private_nonce_payload_t private_nonce_payload_t;
  33
  34 /**
  35  * Private data of an nonce_payload_t object.
  36  *
  37  */
  38 struct private_nonce_payload_t {
  39         /**
  40          * Public nonce_payload_t interface.
  41          */
  42         nonce_payload_t public;
  43
  44         /**
  45          * Next payload type.
  46          */
  47         u_int8_t  next_payload;
  48
  49         /**
  50          * Critical flag.
  51          */
  52         bool critical;
  53
  54         /**
  55          * Length of this payload.
  56          */
  57         u_int16_t payload_length;
  58
  59         /**
  60          * The contained nonce value.
  61          */
  62         chunk_t nonce;
  63
  64         /**
  65          * @brief Computes the length of this payload.
  66          *
  67          * @param this  calling private_nonce_payload_t object
  68          */
  69         void (*compute_length) (private_nonce_payload_t *this);
  70 };
  71
  72 /**
  73  * Encoding rules to parse or generate a nonce payload
  74  *
  75  * The defined offsets are the positions in a object of type
  76  * private_nonce_payload_t.
  77  *
  78  */
  79 encoding_rule_t nonce_payload_encodings[] = {
  80         /* 1 Byte next payload type, stored in the field next_payload */
  81         { U_INT_8,                      offsetof(private_nonce_payload_t, next_payload)         },
  82         /* the critical bit */
  83         { FLAG,                         offsetof(private_nonce_payload_t, critical)             },
  84         /* 7 Bit reserved bits, nowhere stored */
  85         { RESERVED_BIT, 0                                                                                                               },
  86         { RESERVED_BIT, 0                                                                                                               },
  87         { RESERVED_BIT, 0                                                                                                               },
  88         { RESERVED_BIT, 0                                                                                                               },
  89         { RESERVED_BIT, 0                                                                                                               },
  90         { RESERVED_BIT, 0                                                                                                               },
  91         { RESERVED_BIT, 0                                                                                                               },
  92         /* Length of the whole nonce payload*/
  93         { PAYLOAD_LENGTH,       offsetof(private_nonce_payload_t, payload_length)       },
  94         /* some nonce bytes, lenth is defined in PAYLOAD_LENGTH */
  95         { NONCE_DATA,                   offsetof(private_nonce_payload_t, nonce)                }
  96 };
  97
  98 /*                           1                   2                   3
  99        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 100       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 101       ! Next Payload  !C!  RESERVED   !         Payload Length        !
 102       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 103       !                                                               !
 104       ~                            Nonce Data                         ~
 105       !                                                               !
 106       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 107 */
 108
 109 /**
 110  * Implementation of payload_t.verify.
 111  */
 112 static status_t verify(private_nonce_payload_t *this)
 113 {
 114         if (this->critical)
 115         {
 116                 /* critical bit is set! */
 117                 return FAILED;
 118         }
 119         if ((this->nonce.len < 16) || ((this->nonce.len > 256)))
 120         {
 121                 /* nonce length is wrong */
 122                 return FAILED;
 123         }
 124
 125         return SUCCESS;
 126 }
 127
 128 /**
 129  * Implementation of nonce_payload_t.set_nonce.
 130  */
 131 static status_t set_nonce(private_nonce_payload_t *this, chunk_t nonce)
 132 {
 133         if (nonce.len >= 16 && nonce.len <= 256)
 134         {
 135
 136                 this->nonce.ptr = allocator_clone_bytes(nonce.ptr, nonce.len);
 137                 this->nonce.len = nonce.len;
 138                 this->payload_length = NONCE_PAYLOAD_HEADER_LENGTH + nonce.len;
 139                 return SUCCESS;
 140         }
 141         return INVALID_ARG;
 142 }
 143
 144 /**
 145  * Implementation of nonce_payload_t.get_nonce.
 146  */
 147 static void get_nonce(private_nonce_payload_t *this, chunk_t *nonce)
 148 {
 149         nonce->ptr = allocator_clone_bytes(this->nonce.ptr,this->nonce.len);
 150         nonce->len = this->nonce.len;
 151 }
 152
 153 /**
 154  * Implementation of nonce_payload_t.get_encoding_rules.
 155  */
 156 static void get_encoding_rules(private_nonce_payload_t *this, encoding_rule_t **rules, size_t *rule_count)
 157 {
 158         *rules = nonce_payload_encodings;
 159         *rule_count = sizeof(nonce_payload_encodings) / sizeof(encoding_rule_t);
 160 }
 161
 162 /**
 163  * Implementation of payload_t.get_type.
 164  */
 165 static payload_type_t get_type(private_nonce_payload_t *this)
 166 {
 167         return NONCE;
 168 }
 169
 170 /**
 171  * Implementation of payload_t.get_next_type.
 172  */
 173 static payload_type_t get_next_type(private_nonce_payload_t *this)
 174 {
 175         return (this->next_payload);
 176 }
 177
 178 /**
 179  * Implementation of payload_t.set_next_type.
 180  */
 181 static void set_next_type(private_nonce_payload_t *this,payload_type_t type)
 182 {
 183         this->next_payload = type;
 184 }
 185
 186 /**
 187  * Implementation of payload_t.get_length.
 188  */
 189 static size_t get_length(private_nonce_payload_t *this)
 190 {
 191         this->compute_length(this);
 192         return this->payload_length;
 193 }
 194
 195 /**
 196  * Implementation of payload_t.destroy and nonce_payload_t.destroy.
 197  */
 198 static void destroy(private_nonce_payload_t *this)
 199 {
 200         if (this->nonce.ptr != NULL)
 201         {
 202                 allocator_free(this->nonce.ptr);
 203         }
 204
 205         allocator_free(this);
 206 }
 207
 208 /*
 209  * Described in header
 210  */
 211 nonce_payload_t *nonce_payload_create()
 212 {
 213         private_nonce_payload_t *this = allocator_alloc_thing(private_nonce_payload_t);
 214
 215         /* interface functions */
 216         this->public.payload_interface.verify = (status_t (*) (payload_t *))verify;
 217         this->public.payload_interface.get_encoding_rules = (void (*) (payload_t *, encoding_rule_t **, size_t *) ) get_encoding_rules;
 218         this->public.payload_interface.get_length = (size_t (*) (payload_t *)) get_length;
 219         this->public.payload_interface.get_next_type = (payload_type_t (*) (payload_t *)) get_next_type;
 220         this->public.payload_interface.set_next_type = (void (*) (payload_t *,payload_type_t)) set_next_type;
 221         this->public.payload_interface.get_type = (payload_type_t (*) (payload_t *)) get_type;
 222         this->public.payload_interface.destroy = (void (*) (payload_t *))destroy;
 223
 224         /* public functions */
 225         this->public.destroy = (void (*) (nonce_payload_t *)) destroy;
 226         this->public.set_nonce = (status_t (*) (nonce_payload_t *,chunk_t)) set_nonce;
 227         this->public.get_nonce = (void (*) (nonce_payload_t *,chunk_t*)) get_nonce;
 228
 229         /* private variables */
 230         this->critical = FALSE;
 231         this->next_payload = NO_PAYLOAD;
 232         this->payload_length = NONCE_PAYLOAD_HEADER_LENGTH;
 233         this->nonce.ptr = NULL;
 234         this->nonce.len = 0;
 235
 236         return (&(this->public));
 237 }
 238
 239